CAS: 171599-83-0, 139755-83-2

Foreign name: Sildenafil

Chemical name: 5-[2-Ethoxy-5-(4-methyl-piperazine-1-sulfonyl)-phenyl]-1-methyl-3-propyl-1,3a,6,7a-tetrahydro-pyrazolo[4,3 -d]pyrimidin-7-one

Translated Name: Xi Duofen

Purity (content): 99.8% or more

Molecular formula : C22H30N6O4S

Molecular weight: 474.58

Melting point: 187 ~ 189 ° C

EINECS number: 252-082-4

This product is an oral medication for the treatment of penile erectile dysfunction (ED). It is a citrate of sildenafil, a selective inhibitor of phosphodiesterase type 5 (PDE5) specific for cyclic guanosine monophosphate (cGMP). Mechanism of action: The physiological mechanism of penile erection involves the release of nitric oxide (NO) in the corpus cavernosum during sexual stimulation. NO activation of guanylate cyclase leads to an increase in the level of cyclic guanosine monophosphate (cGMP), which causes smooth muscle relaxation and blood filling in the sponge.

1. Pharmacodynamics sildenafil on penile erectile response: sildenafil (Sildenafil, Viagra, Viagra) is a highly selective phosphodiesterase 5 (PDE5) inhibitor, PDE5 is highly expressed in the corpus cavernosum, In other tissues (including platelets, blood vessels and visceral smooth muscle, skeletal muscle), expression is low. Sildenafil enhances the nitric oxide (NO)-cGMP pathway by increasing PDN5, increasing cGMP levels and causing relaxation of the corpus cavernosum smooth muscle, which causes a natural erectile response to sexual stimulation in patients with erectile dysfunction. The erectile response generally increases with increasing doses of sildenafil and plasma. Experiments have shown that the efficacy lasts for up to 4 hours, but the response is weaker than 2 hours. Sildenafil response to the myocardium: PDE5 is not present in normal or diseased cardiac conduction tissues, cardiomyocytes, endothelial cells, or lymphoid tissues, so sildenafil (PDE5 inhibitor) has no positive inotropic effect and cannot Directly affect myocardial contractile function.

Effect of sildenafil on cardiac parameters: Normal male volunteers received a single oral dose of sildenafil 100 mg without clinically significant ECG changes. Eight patients with stable ischemic heart disease were intravenously injected with a total of 40 mg of sildenafil under Swan-Ganz catheter monitoring. Results: At rest, the patient's systolic and diastolic blood pressure was lower than baseline. They dropped by 7% and 10% respectively. Resting right atrium, pulmonary artery pressure, pulmonary wedge pressure, and cardiac output decreased by 28%, 28%, 20%, and 7%, respectively. Although this intravenous dose was 2 to 5 times higher than the mean peak plasma concentration of single dose of sildenafil 100 mg in healthy male volunteers, the above hemodynamic response remained during exercise.

During sexual stimulation, non-renal aergic non-cholinergic neurons of the corpus cavernosum and vascular endothelial nitric oxide synthase catalyze the synthesis of nitric oxide by L-arginine, which activates guanylate cyclase to cyclize Increased guanosine synthesis, which in turn causes relaxation of the smooth muscle of the corpus cavernosum and smooth muscle of the arterioles, and blood is injected into the cavernous sinus of the penis, causing the penis to erect. At the same time, cyclic guanosine monophosphate is further hydrolyzed by phosphodiesterase.

Main components and chemical names: 1-[4-ethoxy-3-[5-(6,7-dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazole[4 , 3d] pyrimidine)] benzenesulfonyl]-4-methylpiperazine decanoate This product is a blue diamond-shaped film coat, which is a white powder after removing the film coat.

Role: erectile dysfunction

Sildenafil citrate "Taiwan is called Weierang, Taiwan Weierang prescription drugs, the scope of indications is limited to a drug that was originally developed by Pfizer Pharmaceutical Company in the United States for the treatment of angina pectoris. The trial found that its effect on the treatment of angina is general, but has a special effect on the treatment of impotence. This accidental discovery prompted manufacturers to declare drugs for the treatment of impotence. The US Food and Drug Administration (FDA) on March 27, 1997 The drug was officially approved as a special drug for the treatment of impotence.

The effects of sildenafil on vision: Studies have shown that this product has no effect on vision, retinal current map, intraocular pressure and optic papilla size when taking twice the maximum recommended dose. It can be distinguished by a transient blue-green color. Whether used alone or in combination with aspirin, this product has no effect on human bleeding time. In vitro, this product enhances the anti-human platelet aggregation of sodium nitroprusside (NO donor). After a single dose of oral sildenafil 100 mg in healthy volunteers, sperm motility and morphology were not affected.

Adverse reactions: headache, flushing, indigestion, nasal congestion and visual abnormalities. Visual abnormalities are mild and transient, mainly manifested by pale color, enhanced light perception or blurred vision.

Dosage: used as tablets, capsules, hot drinks, etc., the dosage is 130-180 mg, the onset time: 15 minutes, duration: 3 days.

Advantages: Sildenafil citrate has the advantages of low dosage, very few side effects, and is soluble in hot water and ethanol.